Liquid fuel burner



A. H, BALLARD LIQUID FUEL BURNER rJune 28, 1932..

June 28, 1932.

A. H. BALLARD LIQUID FUEL BURNER Filed July asf 195o 5 Sheets-Sheet 2June 28,l 1932. A H BALLARD 1,865,390

LIQUiD FUEL BURNER 5 Sheets-Sheet 5 I.. Q @j 1 H n n ,Um ru Aw n D\ l Ho 11| mb H {lllnuflw .xllill) u Patented June 28, 1932 UNITED STATES'-PATENT OFFICE ARTHUR H. BALLARD, OF BOSTON, MASSACHUSETTS, ASSIGNOR TOARTHUR H. BAL- LARD, INCORPORATED, 0F BOSTON, MASSACHUSETTS, ACORPORATION OF MASSA- CHUSETTS LIQUID FUEL BURNER Application led J'uly23,

This invention relates to liquid fuel burners and more particularly toburners of the so-called gun type where the liquid fuel is dischargedunder high pressure into the combustion chamber'through a relativelysmall` nozzle orifice. f

, In burners of the high pressure gun type the liquid fuel is commonlydrawn from a supply tank through the suction of a pump which dischargesthe oil through some pressure-regulating device, such as alpressurerelief valve, the latter serving to by-pass a certain amount offuel back to the pump suction when the pressure exceeds the desiredamount, so that the fuel delivered to the nozzle is delivered through afuel delivery pipe at a. substantiallyl constant pressure. Thisarrangement involves the employment of numerous joints and connectionsbetween the high pressure side of the pump and the lfuel delivery pipewhich must be so constructed as to prevent leakage under the highpressure employed, the latter ordinarily ranging from approximately 100to 150 pounds to the square inch. If leakage develops under the highpressure used, either through improper packing or faulty connection, theamount of liquid fuel leaking out may not only be considerable anda'source of annoyance or even danger, but the fault in the pump or pipeconnection may be aggravated with continued operation of the burner sothat the rate of leakage will rapidly increase. source of trouble andan. element of danger which is not present where low pressure deliyeryis utilized.

The present invention aims to meet this condition by providing adrainage chamber adapted to catch and retain the leakage which mayresult from the development of a fault in the connections on the highpressure side of the pump and by providing in conjunction with this a.leakage responsive device such as a float so that, Aif the leakageaccumulates to an amount indicating something wrong in the connections,the driving motor for the pump is cut out of operation. This not onlyprevents any slight leakage from spreading over the floor, but serves asa warning and It may therefore become both a 1930. serial Np. 469,984.

safety device giving an indication when such leakage has reached a pointwhere it is serious and where attention should be given to the pumpconnections before the burner is further operated.

In the illustrative form of the invention this office is carried out byenclosingv the pump, together with the pressure regulating valve andother high pressure connections, in a small tank-like casing which isequipped with a float and provided with a oat-actuated cut-out switchadapted to cut out the burner motor when and ifthe leakage accumulatesto a substantial depth in the bottom of the casing. f

The invention will be best understood by reference to the followingdescription when taken in connection with the accompanying illustrationof one specific embodiment thereof, while its scope will be moreparticularly pointed out in the appended claims.

In the drawings:

Fig. 1 is a plan view showing the pumpenclosing casing in its relationto the delivery nozzle, blower and driving motor;

Figi 2 is a sectional elevation on an en- Fig. 3 is a plan view on anenlarged scale showing the enclosing casing for the pump, together withthe pump, pressure-regulating valve and connections and also aswitch-controlling float; and

Fig. 4 is an elevation of the casing showing the switch mounted on theside thereof.

Referring to the drawings and to the embodiment of the invention whichis there shown for illustrative purposes, the latter is embodied in awell known type of burner comprising the fuel delivery pipe 11 whichextends through a surrounding tubular air ydelivery shell 13, the latterentering the side of the furnace 15. The end ofthe pipe has a nozzle 17with a relatively small aperture through which fuel in liquid Vformisdischarged into `the combustion chamber 19 under high pressure and in amore or less atomized condition.

The shell is connected to the delivery end of a rotary blower fan 21driven by the electric motor 23, the blower serving to discharge airthrough the tubular shell into the combustion chamber about the nozzle.The current of air delivered through the shell is preferably given arotary or whirling movement by the stationary inclined blades 25 mountedwithin the shell. The combustible mixture of air and atomized fuel isignited by the electric ignition provided through the electrodes 27connected to a suitable source of electricity.

At the side of the blower casing there is provided an enclosed casing ortank 29 of boxlike shape having the cover 31 (Figs. 1 and 4) which is ofcurved contour in side elevation to conform to the contour of the blowercasing. Within this casing there is mounted the pump 33 (Fig. 3) adaptedto be driven by an end of the motor shaft which extends through theblower, there being also contained within the casing the pressureregulating or relief valve 35 together with the various pipe connectionsbetween the pump and fuel supply pipe 36, between the pump and the valveand between the valve and the fuel delivery pipe 11.

The fuel supply pipe 36 for the liquid fuel, which for purposes ofdescription may be assumed to be oil, is connected to the main supplytank, diagrammatically Arepresented at 37. and enters through the sideof the casing 29, being connected to the pump suction through theconnection 38. The pump may be of any suitable type, but is herein ofthe eccentric, rotary, positive-displacement type capable of deliveringthe oil under a pressure of from to 150 pounds to the square inch. Itdischarges the oil to the pressure regulating valve 35 through the pipe39 having the connections 41 and 43 respectively to the pump and thevalve.

The regulating valve may be of any suitable type, the constructionherein employed being shown in Fig. Q. The oil entering the valvechamber 45 through the inlet 47 is discharged to the burner nozzle 17through the nozzle supply passage 49 controlled by the valve 51. Thelatter is moved to a closed position when the pressure drops below apredetermined minimum and opened when it rises above a predeterminedmaximum, its movement-*being effected by the plunger 53 controlled bythe diaphragm 55, the tension of which may be adjusted by the spring 57and adjusting screw 59. If the pressure tends to exceed thepredetermined amount the contraction of the diaphragm moves one 'end ofthe pivoted rocker arm 61 against the spring 63, the opposite end of thearm withdrawing from the head of the spring-opened, by-pass valve 65which thereupon serves to by-pass a certain amount of the oil backthrough the by-pass passage 67 to the pump suction, thereby serving togovern the pressure of the oil delivered to the nozzle and maintain itwithin the desired limits.

The nozzle supply passage 49 is connected (Fig. 3) to the nozzledelivery pipe 11 by the short connecting pipe 69 having the connection71 to the valve and the connection 73 to the fuel delivery pipe, bothconnections being within the tank or casing 29, and the fuel deliverypipe entering the casing through the side walls thereof. The by-passpassage 67 has connection to the by-pass pipe 75 which in turn isconnected to the oil supply pipe 36 leading back to the pump suction.Preferably a straining device (not shown) is inserted in the fuel supplypipe between the connection thereto of the by-pass 75 and the pumpsuction 38, which strainer will serve to clean the oil and to cool theoil bypassed through the regulating valve.

The pump pressure regulating valve and the principal pipe couplings andfittings which carry the high pressure oil are accordingly enclosedwithin the casing 29. Under normal conditions the latter contains noaccumulation of oil. In the event that any leakage of the oil occurs,however, the oil drains down into the casing to be retained in thebottom thereof where it is prevented from spreading over the floor areaor occasioning any damage or inconvenience and prevented from becoming afire hazard.

Any slight leakage of the oil will effect no change in the operation ofthe burner, but, if a fault develops which permits a continued orincreasing leakage of oil and which calls for attention or repair i'nthe pump connections, the accumulation in the bottom of the casing willfinally lift the float 77 (Figs. 3 and 4), contained within the casingand guided for vertical movement by the stationary guiding ring 79, sothat the float will finally reach an elevation where it acts to cut outthe motor and stop the further action of the burner.

To this end the float has connected thereto (Figs. 3 and 4) an uprightrod 8l, the upper end of which is pivotally connectedtothe arm 83, theopposite end of the arm being secured to the rock shaft which isjournaled in and extends through the side wall of the casing and isadapted on the rise of the float to impart a tilting movement to thecut-out switch 87 which is mounted on the end of the rock shaft in anenclosed compartment 89 at the side of the casing. This switch may be ofany suitable type, but herein it is of the mercury tube form comprisingan enclosed glass tube mounted on the rock shaft and containing a smallquantity of mercury. The tube normally tips to such a position that thetwo sealed-in, separated terminals of the lead wires 90 and 91 whichform part of the motor circuit are immersed in the mercury andelectrically connected, maintaining the motor circuit closed at thatpoint. The tube is l vlected and held in the tank and from spreading onthe adjoining oor area, but if it-becomes abnormal the float acts toopen the motor circuit, serving as a warning to indicate that attentionshould be given to the pump or pipe connections and as an automaticcut-out to stop the burner until such attention has been accorded it.

While I have herein shown and described for the purpose of illustrationone specific embodiment of the invention, it is to-be understood thatthe same may be applied to burners of different type of constructionfrom that shown and that extensive deviations and changes may be made inthe character of the elements employed in the combination and in themechanical construction and relative arrangement of parts, all Withoutdeparting from the spirit of the invention.

Claims: ,n

1. In a liquid fuel burner, the combination with a nozzle, of a mainfuel supply tank, a motor driven pump for withdrawing fuel from the tankand delivering it to the nozzle under relatively high pressure,connections providing a circulating system from the tank through thepump to the nozzle including a pressure regulating valve between thepump and the nozzle having a pressure controlled by-pass for returningliquid fuel to the suc-` tion side of the pump, a closed casingenclosing said pump and valve and providing a normally empty leakageretaining chamber adapted to hold and receive leakage from the highpressure connections and prevent the escape of fuel odors at alltimesand avoid fire hazard, 'a ioat in said chamber responsivev to theaccumulation therein of fuel leakage, and a switch for cutting out saidmotoren/the riseof said fioat whereby normal leakage is confined in saidcasing and abnormal leakage stops the operation ofthe burner;

2. A liquid fuel burner of the high pressure gun type having a liquidfuel supply tank and a nozzle, a high pressure pump with connectionsproviding a circulating system Afrom the tank through the pump to thenozzle including pressure regulating means adapted to deliver fuel inliquid form at a relatively high pressure to the nozzle, a closedrevented of the pump' casing independent of said circulating systemenclosing said pump and the high pressure connections thereto includingsaid pressure regulating means and presenting a leakage chamber adaptedto retain leakage of fuel therefrom and to prevent the escape of fuelodors and avoid fire hazard at all times, a float in said chamberresponsive to the accumulation of liquid therein, and means responsiveto the movement of said float by an abnormal accumulation in saidchamber to stop the operation of the burner.

3.\A liquid fuel burner of the high presi s ure gun type having a fuelsupply tank, a nozzle and a high pressure pump with connectionsproviding a circulating system from the tank through the -pump tothenozzle adapted to deliver fuel in liquid form at a relatively highpressure to the nozzle, means associated with the pump and all the high`pressure connections to the nozzle therefrom where leakage may occurcomprising a 'closed casing providing a drainage chamber adapted toreceive fuel leakage from the pump and all such high pressureconnections to prevent the escape of fuel odors at all times and avoidfire hazard, and means responsive to the accumulation of leakage thereinto cut said burner out of operation.

4. A liquid fuel burner of the type having a nozzle and a high pressurepump connected to deliver fuel in liquid form at a high ressure to thenozzle, a casing enclosing all' igh pressure connections between thepump and the nozzle where leakage may occur comprising a drainagechamber adapted to receive fuel leakage from said high pressureconnections, said casing being closed to prevent the escape of fuelodors at all times and avoid iire hazard, and means `associated withsaid chamber responsive to the accumulation of leakage for cutting theburnerout of operation.

5. In a liquid fuel burner of the high pressure gun type embodying aliquid fuel nozzle and means for introducing air adjacent thereto, amotor, a fan driven by said motor for supplying air to said means, afuel supply tank, a pump driven by said motor for withdrawing fuel fromsaidtank and supplying it in liquid form under relatively high pressureto said nozzle, vconnections providing a circulating -system 'from thetank and fire hazard at all times, and abnormal leakage stops theoperation of said fan and pump.

6. A liquid fuel burner of the high pressure gun type having a fuelsupply tank .and

a nozzle, a high pressure pump with conneci tions providing a closedcirculating system from the tank through the pump to the nozzleincluding pressure regulating means adapti ed to deliver fuel in liquidform at a relatively high pressure to the nozzle, a closed casingcompletely enclosing said pump and pressure regulating means andpresenting a closed leakage chamber adapted to retain leakage of fuel,and means responsive to the accumulation of liquid in said chamber forcutting said burner out of operation whereby normal leakage is confinedin a closed casing avoiding odors and fire hazard at all times andabnormal leakage stops the operation of the burner.

7 In combination with a liquid fuel burner 1 embodying a source ofliquid fuel, a burner nozzle, a high pressure pump connected to receiveliquid fuel from said source, and for conducting liquid fuel under'connections high pressure from said pump to said nozzle; a drainagechamber comprising a closed casing embracing all high pressureconnections between the pump and the nozzle Where leakage may occur totrap and retain such leakage and prevent escape of fuel odors at alltimes and avoid ire hazard, and means associated with said chamber tostop the operation of said pump in response to accumulation of leakageby said chamber.

In testimony whereof, I have signed my name to this specification.

ARTHUR H. BALLARD.

